Cutlery-bolster-grinding machine



4 SheetsSheet 1.

A. JOHNSTON. GUTLERY BOLSTER GRINDING MACHINE.

No. 534,396. 'Patented Feb. 19, 1895.

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m: NORRIS PtrERs col, FNOTO-LITHD.. wmmumu n c 4 Sheets-Sheet 2.

(No. Model.)

A JOHNSTON GUTLERY BOLSTERGRINDING MACHINE.

Patented Feb. 19, 1895.

fl-Wnesses 4 Sheets-Sheet 3.

(No Model.) l A! JOHNSTON.

GUTLERY BOLSTER GRINDING MACHINE.

N0. 534,396. Patented Feb. 19, 1895.'

- (No Model.) 4 Sheets-Sheet 4.

A. JOHNSTON. GUTLERY BOLSTER GRINDING MACHINE.

No. 534,896. Patented Feb. 19, 1895.

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fizz hawk n nonms PETERS co. wm'ouma, WASHINGTON, u. c.

UNITED STATES PATENT OFFICE.

ALLEN J OHNSTON,OF OTTUMWA, IOWA.

CUTLERY-BOLSTER-GRINDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 534,396, dated February19, 1895. Application filed October 16,1894. Serial No. 6 6.068- 1N0 modl.

' ful Improvement in Outlery-Bolster-Grinding Machines, which is fullyset forth in the following specification.

This invention has reference to mechanism for grinding the bolsters oftable knives and forks, and its object is to provide automatic machineryfor that purpose. Prior tothis invention these parts of knives and forkshave been ground by hand.

The bolster is of irregular form, being, like the handle itself, nearlyflaton the sides and sharply curved on the edges. This applies both tothe top or ridge of the bolster and to the neck or groove. According tothe present invention the knife or fork is held loosely in a revolvingholder, and the handle is pressed with yielding pressure against a rest,which limits and determines the position of the work with reference tothe grinding wheel. Consequently the handle itself acts as a former,causing the wheel to grind to'the required depth at all points, and to ashape corresponding with the outline of the handle. If a different shapeis required for the bolster, a separate former may be slipped onto thehandle of the knife or fork.

The grinding wheel necessarily has a thin edge, and hence is quicklyworn away. To compensate for wear the wheel is mounted on a slide as iscommon. To keep the .edgeof the wheel in proper shape a truing tool ordevice is provided, which tool is journaled and movable across the edgeof the wheel in a line corresponding to the required shape of thelatter. The support of the truing tool is also adjustable toward theaxis of the wheel so that its position may be changed as the wheel wearsaway.

Other features of the invention will be pointed out in the followingdetailed descripthat is, a machine with two grinding Wheels, andaccessory parts. 7

As shown the wheel 0' to the right (Figs. 1 and 2) is used to grind thetop or ridge of the bolster, and that to the left (0 the hollow or neck.This is merely a matter of convenience since the work could be done ondifferent machines, or on the same machine with difierent wheels.

The frame-work and many of the moving main shaft suitably mounted inbearings in frame A. I

The means for communicating motion to the several moving parts, whichmeans constitute no part of the present invention, will be brieflydescribed.

Shaft O communicates motion to a friction wheel D, whose shaft is journaled in a swing-.

ing frame f pivoted to the main frame at f (Fig. 4). Wheel D is throwninto and out of gear with the main shaft as hereinafter described. Onthe shaft of wheelD is a pinion d, which drives a gear E. Thelatter-through pinion e and gear E drives the revolving work-holder M.

Frame f has an arm f extending forwardly through a slot in frame A, andto the end of the arm is pivoted a connecting rod T pivoted at its lowerend to a treadle T. The latter is pivoted to baseB at K and. at itsinner end carries a latch t which when the machine is in operation restson the rim 5 of a ratchetwheel S, as shown in Fig. 2. In that positionrod T holds up frame f, keeping wheel D in engagement with the mainshaft. This engagement continues until a pin 5 on rim 8 dislodges latcht from its seat on the latter, permitting treadle T and frame f to drop,and

arresting the movements of the parts driven from wheel D.

Wheel E, above referred to, has on one face a cam surface 6 (Fig. 2)which oscillates a lever G which carries at its lower end a pawl g inengagement with the ratchet-wheel S. The latter thus moves step-by-stepat a slow speed compared with that of the holder, until one revolutionis completed, when the action of pin 8 on latch t takes place as abovede scribed. V

Treadle T is connected also with a pitman U which at its upper end ispivoted to the finger P by which the work is pressed against thegrinding wheel. Finger 1? is also pivoted to its support at 19' (Figs. 3and 4). Consequently when the inner end of treadle T descends, as abovedescribed, pitmanU is raised throwing holding finger P away from thework, asindicated in dotted lines. When the outer end of treadle T isdepressed, raising the inner end and engaging latch 25 with the rim ofwheel S, the holding finger P is by the same movement brought intooperation against the handle of the knife or fork.

The parts mentioned in the foregoing description are duplicated in thedouble-machine shown in the drawings, but one description snffices forboth sets of mechanism.

The revolving work-holder M has a hollow socket to receive and hold theblade .2 of a knife or fork, and is adjustable to varying lengths ofwork by means of a nut m in a well known manner. The handle Z of thearticle to be ground rests at its end against an adjustable stop 11,carried by the support 0 of the work holder. This support has an uprightplate 0 in which are secured the outer ends of the bent rods 19, whichconstitute the rest for the handle Z and whose position determines thedepth of cut of the grinding wheel. Holding finger P lies between thetwo rods 13 and presses the blade toward the upright positions of thelatter, permitting the wheel to out until the motion of the handleagainst the wheel is arrested. The pressure of finger P is yielding sothat, as the article turns presenting alternately its sides and edges tothe wheel the finger moves sufficiently to compensate for the differencebetween the thickness and width of the handle. This yielding pressure iseffected by the action of a spring 10 which surrounds the up per part ofpitman U. This part is tubular, and in it slides the end of the lowerpart U, which carries a pin 1L3, projecting through a slot in tubularpart U. Spring of is compressed between this pin at its upper end, andthumb'nut u at its lower end, and its pressure may be varied by turningsaid nut in one direction or the other.

Although it will be understood from the foregoing description that therotation of the handle will (owing to the difference between thethickness and width thereof) through the movement of the finger P causea slight variation in the pressure exerted by the spring a during eachrevolution of the handle, such variation is not of the essence of theinvention herein. Means for varying the pressure of the handle againstthe grinding or polish ing wheel, are, however, broadly claimed in mypending application, filed of even date herewith, and serially numbered526,067.

From the foregoing description it will be understood how the bolster isautomatically ground to proper depth' at all points.

The edge of the grinding wheel being quite thin would quickly lose itsproper shape unless means to prevent it were provided. Such meanscomprises a truing tool Q carried by a pivoted arm Q, and having ahandle q for conveniently moving it. across. the edge of the wheel.Wheel 0 which grinds the top of the bolster should have simply a planeflat edge. Consequently the truing tool is arranged to move directlyacross the edge, as shown in Figshl, 2 and 3. Wheel 0 which grinds thehollow or neck must have a rounded edge. Consequently its truing deviceis pivoted as shown in Fig.1, so as to swing in an arc corresponding tothe curved outline of the edge. The support Q to which arm Q is pivotedis mounted to slide in a standard Q and provided with an adjusting wheelq, so that the tool may be adjusted toward the axis of the wheel as thelatter wears away.

Each grinding wheel has its arbor c supported in hearings in a slidemounted on an extension C of the frame, the arbor being provided with adriving pulley 0 The slide 0 may be moved to bring the wheel nearer toor farther from the work by any suitable means, such as an adjustingscrew 0 provided with an operating handle a.

It will be obvious from the foregoing description that parts of theinvention may be used without others, and that modifications may be madein details of construction.

\Vhat I claim is-- 1. In a machine for grinding the bolsters oftable-knives and forks, the combination with the grinder, of a revolvingwork-holder, a fixed rest for the handle of the article, and means forpressing the handle during grinding against the rest with yieldingpressure whereby the handle acts as a former to de termine the shape ofthe bolster, substantially as described. I

2. The combination with a grinding wheel having its edge conformed tothe shape to be given the bolster of a knife or fork, of a workholder,means for revolving the holder with the Work in contact with thegrinding-wheel, a fixed rest against which the handle bears during thegrinding, and a spring-actuated finger pressing the handle against therest with yielding pressure whereby the handle acts as a former todetermine the shape of the bolster, substantially asdescribed.

3. The combination with the grinding-wheel, of a revolving work-holderfor holdinga knife or fork, a rest embracing. the handle of the articleon two sides, a spring-actuated finger ing holder and throwing back thefinger after pressing the handle against the rest and the the grindinghas proceeded for a predeterbolster against the wheel with yieldingpressmined time, substantially as described. ure, substantially asdescribed. In testimony whereof I have signed this 5 4. The combinationwith the grinding-wheel, specification in the presence of two subscrib-15 of a revolving work-holder, a fixed rest eming witnesses,

bracing the handle of the article being ground ALLEN JOHNSTON. on twosides, a spring-actuated finger bear- Witnesses: ing against the handleon the third side, and A. G. HARROW,

I 0 means for automatically arresting the revolv- ALFRED BRIGGS.

